Operation of a user interface may involve contact between a user and a surface of the user interface. For example, a digit of a user may contact a surface of the user interface. Such contact may cause a contaminant to be deposited on the surface of the user interface. A contaminant, located on the surface of the user interface may affect performance of the user interface, or it may affect appearance of the surface of the user interface. One type of user interface, which may be affected in this way, is an electrotactile user interface.
An electrotactile user interface may comprise a conductive layer located under a dielectric layer. A digit of a user placed on the dielectric layer may result in formation of a capacitance between the conducting layer and subcutaneous tissue that is at least partly conductive. An alternating potential applied across this capacitance may result in variation in electrostatic force between the digit and the conducting layer, it may also result in variation of friction perceived by the user when the digit is moved across the dielectric layer.
The listing or discussion of a prior-published document or any background in this specification should not necessarily be taken as an acknowledgement that the document or background is part of the state of the art or is common general knowledge. One or more aspects/embodiments of the present disclosure may or may not address one or more of the background issues.